Apparatus for moving tape incrementally past a recording head

ABSTRACT

This invention relates to an incremental data recording apparatus for moving tape incrementally past a recording head for recording data on the tape. More particularly, the invention relates to an incremental tape recording apparatus having a rotatable capstan shaft against which tape is pressed, the rotation of the capstan shaft serving to advance the tape, a continuously rotated flywheel supported about the capstan the shaft, a drive collar affixed to the capstan shaft and adjacent the flywheel, both the drive collar and flywheel having a reduced diameter shoulder portion coaxial with the capstan shaft and adjacent each other, a coil spring received about the shoulder portions of the drive collar and flywheel, the spring being wound such that the direction of rotation of the flywheel tends to wind the spring tight about the flywheel shoulder and drive collar shoulder to rotate the drive shaft, the spring having a radially extending tang at one end, a tubular ratchet member received about the spring having a notch therein receiving the tang, the ratchet member having a dog extending from the external surface, and a ratchet release bar normally engaging the ratchet member dog to prevent the rotation of the spring, the ratchet release bar being movable out of contact with the ratched dog whereby the rotation of the flywheel rotates the spring and thereby the drive collar and capstan shaft, the capstan shaft rotating until the ratchet release bar is repositioned to engage the ratchet member dog.

O United States Patent m1 3,595,499

[ Inventor Robe Chins Primary Examiner-Leonard D, Christian Tulsa, Okla Attorney-Head & Johnson [2]] Appl No 878.820 [22] Filed Nov. 2!, 1969 {45] Patented July 27, 1971 ABSTRACT: This invention relates to an incremental data [73] Assignee The Telex Corporation recording apparatus for moving tape incrementally past a Tulsa, Okla. recording head for recording data on the tape. More particularly, the invention relates to an incremental tape recording apparatus having a rotatable capstan shaft against which tape is pressed, the rotation of the capstan shaft serving to advance [54] APPARATUS FOR MOVING TAPE the tape, a continuously rotated flywheel supported about the INCREMENTALLY PAST A RECORDING HEAD capstan the shaft, a drive collar affixed to the capstan shaft 6 u 6 Drawing Figs. and ad acent the flywheel, both the drive collar and flywheel having a reduced diameter shoulder portion coaxial with the {52] US. Cl 242/206, capstan Shaft and adjacent each other a coil spring received 226/188 about the shoulder portions of the drive collar and flywheel, [51 I Int. Cl Bl lb /32, the Spring being wound Such that the direction of rotation of G03) 1/04 the flywheel tends to wind the spring tight about the flywheel (50] Field Of Search 242/206, Shouider and drive collar Shoulder to rotate the drive Shaft the 226/120 157; 179/1002 spring having a radially extending tang at one end, a tubular 56 ratchet member received about the spring having a notch l Renal-woes Cited therein receiving the tang, the ratchet member having a dog UNITED STATES PATENTS extending from the external surface, and a ratchet release bar 2,9l7,250 12/ 1959 Bodenstein 242/188 X normally engaging the ratchet member dog to prevent the 2,977,059 1961 /1 rotation of the spring, the ratchet release bar being movable 5 1962 Roberts 1 -2 out of contact with the ratched dog whereby the rotation of 3.143.310 1 4 Nord n 242/ 208 the flywheel rotates the spring and thereby the drive collar and 3,332,084 7/ 7 hr r a 346/74 capstan shaft, the capstan shaft rotating until the ratchet 3,389'399 1963 Ke nedy 74 release bar is repositioned to engage the ratchet member dog.

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' sum 1 OF 2 INVEN TOR.

. 2 ROBERT L,.CRAFTS ATTORNEYS PATENTED m2? I97! 3, 595499 sum 2 or z INVENTOR.

ROBERT L CRAFTS ZVMJfW ATTORNEYS APPARATUS FOR MOVING TAPE INCREMENTALLY PAST A RECORDING HEAD CROSS-REFERENCE This disclosure is not related to any pending United States v or foreign patent application.

BACKGROUND AND OBJECTS OF THE INVENTION Magnetic tape systems are frequently used today to store data for subsequent use. A tape data storage system consists basically of a magnetic tape, record and playback heads, or a combination record-playback head, and means of moving the tape past the record-playback head. A typical system includes the arrangement wherein the tape is moved by a rotating capstan against which the tape is pressed, such as by means of a pinch roller. As long as the capstan is rotating the tape is moved past the recording head.

It is sometimes necessary to store data on a tape in which the data is not presented at a continuous rate, such as when the data is in the form of time spaced multibit character signals. A continuously moving tape results in much of the tape not being used for data storage since much tape travel occurs between the receipt of individual data characters. When the tape is played back there may also be a substantial time loss, and the length of tape necessary to record and playback a given amount ofdata will, in such cases, be excessive.

This invention provides an incremental recording apparatus utilized to record and playback data in either digital or analog form. The invention is particularly useful in recording data signals received in multibit form such as those generated by a teletypewriter or similar device. These signals are typically generated in serial or parallel groups of bits to form individual characters. The recorder to be described includes arrangement for recording such data in incremental form, one increment of tape moving for each character recorded, with the tape remaining stationary during the interval between recording increments.

It is therefore an object of this invention to provide an incremental tape recording apparatus.

More particularly, an object of this invention is to provide an incremental recording apparatus for moving tape past a recording head for recording data thereon, the tape being moved in incremental steps.

A more particular object of this invention is to provide a mechanism for incrementally moving tape, the mechanism including a coil spring normally retained in a nonrotated position and, upon release of the coil spring, motion is transmitted from a continuously rotating flywheel to a capstan drive shaft.

These objects, as well as other objects of the invention, will be understood by reference to the description and claims taken in conjunction with the drawings.

DESCRIPTION OF THE VIEWS FIG. I is a top view of a portion of a tape recording apparatus.

FIG. 2 is a cross-sectional view taken along the line 22 of FIG. 1, disclosing the details of the incremental tape recording apparatus of this invention.

FIG. 3 is a cross-sectional view taken along the line 3-3 of FIG. 2.

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 2.

FIG. 5 is a partial bottom view of the incremental tape recorder of this invention showing the portions thereof which 1 DETAILED DESCRIPTION Referring to the drawings and first to FIGS. 1 and 2, the numeral 10 indicates a baseplate upon which the major portion of the elements making up the invention are supported. The baseplate 10 includes means to receive a tape cassette 12 thereon, the cassette being of standard design well known in the industry. The tape cassette 12 includes a wind spool 14 and a rewind spool 16 which receive a magnetic tape 18 thereon.

Positioned on the baseplate 10 is a record-playback head 20 which, when the mechanism is in the operating mode, is in contact with magnetic tape 18. A guide 22 insures proper alignment of tape 18 with head 20. An opening 24 in cassette 12 receives acapstan shaft 26 against which tape I8 is pressed by means ofa pinch roller 28. The rotation of capstan shaft 26 causes movement of the tape 18 past record-playback head 20 when the apparatus is in record or playback mode. The mechanism shown in FIG. I is not unlike that of a typical cassette-type tape recorder in which capstan shaft 26 is continuously rotated in the record mode to move tape 18 past head 20.

FIG. 2 shows details of the invention including means whereby the capstan shaft26, rather than being rotated continuously as in the typical tape recorder, is rotated incrementally so that tape 18 is moved only as data, in multibit character form, is actually recorded. FIG. 2 is shown without the cassette 12. A bearing block 30 having an opening therethrough and a bearing 32 at each end is affixed to the base plate 10 and rotatably supports the capstan shaft 26. Rotatably supported on the capstan shaft 26 is a flywheel 34 having an opening therethrough receiving shaft 26 and having bearings 36 which insure low-frictional relationship between the flywheel 34 and the shaft 26. Flywheel 34 includes a groove 38 in the exterior periphery which receives a belt 40 driven by motor 42. When motor 42 is energized flywheel 34 rotates continuously about the capstan shaft 26.

Affixed to the capstan shaft 26 is a drive collar 44 held to the shaft by setscrew 46. Flywheel 34 includes an integral reduced diameter shoulder portion 48 at one end and in like manner the guide collar 44 includes a reduced diameter shoulder portion 50 at the end adjacent the flywheel. The shoulder portions 48 and 50 are of approximately the same external diameter and both are coaxial about shaft 26. In the preferred arrangement the diameter of shoulder portion 50 is 0.001 inch to 0.003 inch larger than the diameter of shoulder portion 48.

Positioned on shoulder portions 48 and 50 is a coiled spring 52. The spring 52 has, at the end thereof adjacent the flywheel 34, a radially extending tang portion 54. The spring 52 is coiled in the direction such that the rotation of flywheel 34 tends to wrap the spring more tightly about the shoulder portion 48 of the flywheel and shoulder portion 50 of the drive collar. Spring 52 has a normal internal diameter slightly less than the external diameter of the shoulder portions 48 and 50 so that frictional relationship between these components normally exists.

Received about spring 52 is a tubular ratchet member 56, the interior diameter of the ratchet member being slightly larger than the exterior diameter of spring 52. A notch 58 in the ratchet member receives the tang 54 of spring 52.

The exterior of drive collar 44 has at least one integral radially dog portion extending from the exterior circumferential surface. In the illustrated arrangement there are two of such dogs, 60A and 60B, spaced l relative to each other on the ratchet member circumferential surface. (See FIGS. 3 and 4.) Supported adjacent the ratchet member 56 is a movable ratchet release bar. In the illustrated arrangement the ratchet release bar is in the form of a plunger 62 of a solenoid 64. A spring 66 normally retains the ratchet release bar, or plunger 62, in position to engage dogs 60A and 603 as the ratchet member 56 rotates, the plunger 62 being withdrawn and out of contact when solenoid 64 is energized.

Referring to H6. 5, a bottom view of the incremental tape mechanism of this invention means is shown whereby the tape is wound as it is moved in steps byincremental rotation of the capstan shaft 26. When the mechanism is in the record mode, an idler wheel 68, supported on an arm 69 engages drive collar 44 and at the same time contacts the periphery ofa wind spool drive wheel 70. A tape wind shaft 72 supports wind spool 14 (see FIG. 1) and the wind spool drivewheel 70. Thus when drive collar 44 and thereby capstan shaft 26 is rotated, whether in incremental steps or continuously, idler wheel 68 transfers such rotary motion to wind spool drive wheel 70 and shaft 72 to thereby rotate the wind spool 14. Arm 69 moves idler wheel 68 into engagement with drive collar 44 and wind spool drive wheel 70 when the apparatus is in the record mode by mechanical linkage mechanism not shown and not a part of the invention.

Since the diameter of the tape wound on wind spool 14 varies with the quantity of tape wound on the spool, the amount of rotation of wind spool 14 is not constant relative to the rotation of capstan shaft 26. For this reason a slip clutch arrangement is required so that the rotation of wind spool drivewhcel 70 will apply a controlled torque to the rotation of wind spool 14 but in a manner such that there is no positive interconnection between the rotation of capstan drive shaft 26 and wind spool 14. This is best shown in the cross-sectional view of FIG. 6. Wind spool drive wheel 70 is rotatably supported about the wind spool shaft 72 which rotates in bearing 73. Afflxed to the wind spool shaft 72 is a wind spool drive collar 74. Between the surface of drive collar 74 and wind spool drive wheel 70 is a felt washer 76. A spring 78 held in place by a cap 80 and retaining ring 82 applies a constant frictional engagement of the wind spool drive wheel 70 to fclt washer 76 and drive collar 74. Thus as the drive wheel 70 is rotated by idler wheel 68 as the capstan shaft 26 is incrementally stepped, such rotation is applied through the slip arrangement of the felt washer 76 to the wind spool drive shaft 72 applying a rotational torque so that tape advanced by the rotation of capstan shaft 26 is wound on the wind spool 14.

DESCRIPTION OF OPERATION When the apparatus is in the record mode tape cassette 12 is positioned such that magnetic tape 18 engages recording head 20 and is held against capstan shaft 26 by the pinch roller 28. Data, such as in the form of teletypewriter transmission, may be incrementally recorded and the use of the apparatus for such purpose will now be described, it being understood that the invention is not limited only to use for this purpose. Each character coming out of the standard teletypewriter transmission system is approximately 100 milliseconds long with individual code bits equally spaced. Each teletypewriter character includes a start bit, seven character bits, a parity bit, and two stop bits. By circuitry which is not a part of this invention, the start bit of each character energizes solenoid 64, withdrawing plunger 62. Continuously rotating flywheel 34 transmits frictional torque to spring 52 which is normally held in nonrotated condition by ratchet 56. When dog 60B of ratchet 56 is released, by the withdrawal of plunger 62, spring 52 immediately tightens about shoulder 48 of the flywheel and shoulder 50 of the drive collar, transmitting rotational torque to drive collar 44. Capstan shaft 26 is rotated and at the same time idler wheel 68 and takeup wheel 70 is rotated by the apparatus previously described. Drive collar 14 continues to rotate until ratchet 46 is stopped. Solenoid 64 is energized by the start bit of the character to be received only for a length of time sufficient to allow dog 608 on the ratchet member 56 to pass and plunger 62 immediately returns to its extended position. Thus, the ratchet member 56 will rotate until the next dog strikes plunger 62. When two dogs 60A and 60B are utilized, as shown best in FIGS. 3 and 4, ratchet member 56 and thereby capstan shaft 26, will rotate 180". During this 180 rotation of capstan shaft 26 the tape 18 is advanced a length equal to one-half the circumference of the capstan shaft 26 at the area at which it is engaged by the tape. This incremental advancement permits the subsequent character data bits of the teletypewriter character to be recorded on tape 18. The tape then stops and remains in the stopped position until the next character is received, the first bit of which is the start bit which results in the function being repeated. In this manner the tape is incrementally advanced only during receipt and recording of a character.

When it is desired to play back the tape it may be played back at a continuous rate thereby transforming the recorded data into electrical signals at a rate much more rapidly than the rate at which the information was incrementally recorded.

It can be seen that the invention may be practiced utilizing a variety of obvious alternate embodiments. As an example, any means of selectably controlling the rotation of ratchet member 56 is within the purview of the invention. Instead of including dog portions 60A and 60B ratchet member 56 may be cylindrical on the exterior surface with plunger 62 having a brake pad on the outer end which engages and stops the rotation of the ratchet member while permitting it to rotate when the plunger is withdrawn.

While the invention 1 has been described with a certain degree of particularity it is manifest that many changes may be made in the details of construction and the arrangement of components. It is understood that the invention is not to be limited to the'specific embodiment set forth herein by way of exemplifying the invention, but the invention is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element or step thereof is entitled.

What I claim:

1. An incremental recording apparatus for moving tape incrementally past a recording head, comprising:

a rotatable capstan shaft against which tape is pressed, the

rotation of the capstan shaft serving to advance the tape;

a continuously rotated flywheel supported about said capstan shaft, said flywheel having, at one end thereof, a reduced diameter shoulder'portion coaxial with said capstan shaft;

a drive collar afflxed to said capstan shaft and having a reduced diameter shoulder portion coaxial with said capstan shaft, said flywheel shoulder and drive collar shoulder being of substantially the same diameter and adjacent each other;

a coiled spring coaxially received about said capstan shoulder and said drive collar shoulder, the normal internal diameter of the spring being slightly smaller than the external diameter of said flywheel shoulder and said drive collar shoulder, the direction of rotation of said flywheel tending to tighten said spring about said flywheel shoulder and said drive collar shoulder, said spring having a radially extending tang at the end thereof received on said flywheel shoulder;

a tubular ratchet member coaxially received about and externally of said spring, the interior diameter of said ratchet member being slightly larger than the external diameter of said spring, said ratchet member having a slot therein receiving said tang of said spring whereby said spring and said ratchet member are rotationally interlocked; I

a ratchet release bar movably supported adjacent said ratchet member and movable between a first and a second position, and arranged such that in said first position said release bar engages said ratchet member preventing the rotation thereof, and in said second position said release bar is removed from said ratchet member and permits the rotation of said ratchet member; and

means of selectably moving said ratchet release bar between said first and second positions.

2. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 1 wherein said ratchet member has a dog portion extending radially from the exterior surface thereof, and wherein said ratchet release bar, in said first position, extends adjacent the exterior surface of said ratchet member and is engaged by said dog portion of said ratchet member preventing the rotation of said ratchet member and in said second position said release bar is removed from adjacent said ratchet member and permits the rotation ofsaid ratchet member;

3. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 2 wherein:

said ratchet release bar and means of selectably moving said ratchet release bar includes a solenoid having a plunger extending therefrom, said solenoid being supported adjacent said ratchet means, said solenoid plunger'being positioned between a first and second position according to the energization of said solenoid, in said first position said plunger engaging said ratchet dog and in said second position said ratchet dog passing said plunger as said ratchet rotates.

4. An incremental recording apparatus for moving a tape incrementally past a recording head for recording data on the tape according to claim 1 including:

a tape winding spindle for receiving tape thereon after said tape has been moved past said recording head by the rotation of said capstan shaft, said tape winding spindle being rotatably supported parallel to said capstan shaft; and

means of rotating said tape winding spindle upon the rotation of said capstan shaft.

5. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 4 wherein said means of rotating said tape wind spindle upon the rotation of said capstan shaft includes:

a drive wheel affixed to said tape wind spindle, said drive wheel being spaced from said drive collar; and

an idler wheel engaging said drive collar and said drive wheel to rotate said drive wheel, and thereby said tape winding spindle, when said drive collar is rotated.

6. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 5 includ mg:

a slip clutch means between said drive wheel and said tape winding spindle 

1. An incremental recording apparatus for moving tape incrementally past a recording head, comprising: a rotatable capstan shaft against which tape is pressed, the rotation of the capstan shaft serving to advance the tape; a continuously rotated flywheel supported about said capstan shaft, said flywheel having, at one end thereof, a reduced diameter shoulder portion coaxial with said Capstan shaft; a drive collar affixed to said capstan shaft and having a reduced diameter shoulder portion coaxial with said capstan shaft, said flywheel shoulder and drive collar shoulder being of substantially the same diameter and adjacent each other; a coiled spring coaxially received about said capstan shoulder and said drive collar shoulder, the normal internal diameter of the spring being slightly smaller than the external diameter of said flywheel shoulder and said drive collar shoulder, the direction of rotation of said flywheel tending to tighten said spring about said flywheel shoulder and said drive collar shoulder, said spring having a radially extending tang at the end thereof received on said flywheel shoulder; a tubular ratchet member coaxially received about and externally of said spring, the interior diameter of said ratchet member being slightly larger than the external diameter of said spring, said ratchet member having a slot therein receiving said tang of said spring whereby said spring and said ratchet member are rotationally interlocked; a ratchet release bar movably supported adjacent said ratchet member and movable between a first and a second position, and arranged such that in said first position said release bar engages said ratchet member preventing the rotation thereof, and in said second position said release bar is removed from said ratchet member and permits the rotation of said ratchet member; and means of selectably moving said ratchet release bar between said first and second positions.
 2. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 1 wherein said ratchet member has a dog portion extending radially from the exterior surface thereof, and wherein said ratchet release bar, in said first position, extends adjacent the exterior surface of said ratchet member and is engaged by said dog portion of said ratchet member preventing the rotation of said ratchet member and in said second position said release bar is removed from adjacent said ratchet member and permits the rotation of said ratchet member.
 3. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 2 wherein: said ratchet release bar and means of selectably moving said ratchet release bar includes a solenoid having a plunger extending therefrom, said solenoid being supported adjacent said ratchet means, said solenoid plunger being positioned between a first and second position according to the energization of said solenoid, in said first position said plunger engaging said ratchet dog and in said second position said ratchet dog passing said plunger as said ratchet rotates.
 4. An incremental recording apparatus for moving a tape incrementally past a recording head for recording data on the tape according to claim 1 including: a tape winding spindle for receiving tape thereon after said tape has been moved past said recording head by the rotation of said capstan shaft, said tape winding spindle being rotatably supported parallel to said capstan shaft; and means of rotating said tape winding spindle upon the rotation of said capstan shaft.
 5. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 4 wherein said means of rotating said tape wind spindle upon the rotation of said capstan shaft includes: a drive wheel affixed to said tape wind spindle, said drive wheel being spaced from said drive collar; and an idler wheel engaging said drive collar and said drive wheel to rotate said drive wheel, and thereby said tape winding spindle, when said drive collar is rotated.
 6. An incremental recording apparatus for moving a tape incrementally past a recording head according to claim 5 including: a slip clutch means between said drive wheel and said tape winding spindle. 